Pressurized fountain pen



Jan. 29, 1963 R. s. TATE PREssuRIzED FOUNTAIN PEN Filed Jan. 18. 1962 INVENTOR.

.A T TORNEYS I' V rI BY W 3,075,497 PREISSURHZED FOUNTAHJ PEN Resseii S. r1`ate, 415 12th St., Worthington, Minn. Fiied `lan. 18, 1962, Ser. No. 167,131 2 Claims. (Cl. 1Z0-42.4)

My invention relates to fountain pens and more particularly to improvements in ball point pens.

Still more specifically, my invention relates to improvements in the conventional mass-produced ball point-type pen wherein the ink or writing liuid ilows from the inkcontaining cartridge to the ball under gravity.

Ball point type pens of the type immediately above described operate in quite satisfactory manner when the point is downwardly disposed with respect to the reser- Voir so that the ink may iiow from the cartridge to the ball. However, under conditions where the pen is held in a horizontally disposed position, or worse yet with the point above the level of the cartridge, the ink does not feed to the ball and writing failure occurs.

The primary obiect of my invention is the provision of novel and inexpensive means whereby the cartridges of conventional ball point pens may be effectively and eiciently pressurized so as to enable the operator to write continuously with the point above the level of the inkcontaining cartridge or reservoir, if desired.

A further object of my invention is the provision of a device of the class above described which incorporates a `minimum of working parts, which is extremely easy to adjust, and which is substantially foolproof in its operation.

A still further obiect `of my invention is the provision of a device oi the class above described wherein the pressurizing mechanism may be added to a conventional ball point pen at such a small cost as to enable the same to be adopted without materially raising the price of the pen to the retailer.

The above and still further objects of my invention will become apparent from the following detailed specification, appended claims and attached drawings.

Referring to the drawings wherein like characters indicate like parts throughout the views.

FIG. 1 is a view in side elevation of a conventional ball point pen illustrating my novel invention; and

FIG. 2 is an enlarged view in axial section taken substantially on the line 2-2 of FIG. 1.

Referring with greater particularity to the drawings, the numeral 1 indicates in its entirety the tubular shell or housing of a conventional ball point pen, the clipequipped cap thereof being identified by the reference character 2. Received within the tubular housing 1 is a tubular ink-containing cartridge or reservoir 3 which terminates at its lower end in a tubular point 4, slidably receivable in the opening 5 in the tapered tip 6 of the housing 1. Mounted for rotation in the extreme lower end. of the point 4 is a conventional writing ball 7.

Projecting axially outwardly from the cap 2 is a plunger S which defines a downwardly opening socket 9 at its lower end within the cap 2. Snugly slidably received within the socket 9 is the extreme upper end 10 of the tubular reservoir 3. In conventional manner depression of the plunger S causes extension of the tip d through the aperture 5 in the lower end of the housing 1 against the bias of a coiled compression spring 11 encompassing the lower end portion of the cartridge 3. Spring 11 is engageable at its lower end with the tapering lower end of the housing 1, as indicated at 12, and at its upper end with a diametrically enlarged portion 13 on the cartridge 3. All of this mechanism is conventional and forms no part of the instant invention.

In accordance with -my invention, an externally threadstates arent of d'ilih?. Fatenteti Jan. 29, 1963 sun ed tubular nut 14 is telescopically slidably received over the intermediate portion of the ink-containing cartridge 3. Preferably and as shown the nut 14 is provided at its lower end with an enlarged knurled head 15 to facilitate imparting rotative adjustments thereto. An internally threaded diametrically enlarged tubular sleeve 16 concentrically encompasses the upper end portion of the cartridge 3 and has screw threaded engagement at its lower end with the upper end of the externally threaded nut 14. Snugly received withinV the tubular sleeve 16, immediately above the tubular nut 14 is a compressible sealing washer 17, said washer 17 being movable in an upward direction `by the nut 14. A compressible annular sealing ring 13 is snugly concentrically received between the cartridge 3 and the upper end of the tubular sleeve 16. It will be noted that the inner cylindrical wall 16' of the sleeve 16, and the cylindrical outer wall 3 of the cartridge 3 define an annular air-tight chamber 19 extending between the sealing elements 17, 18.

Preferably and as shown the cartridge 3, immediately below the sealing ring 18, is provided with an annular circumferential groove Ztl in which is snugly received a snap ring 21. Snap ring 21 obviously positively limits lowering movements of the sealing ring 18 beyond the positions shown in FIG. 2. Finally, in accordance with my invention, the extreme upper end of the cartridge 3 is closed by a compressed rubber plug or the like 22 and a port, identified by the numeral 2,3, is provided for cornmunication between the interior of the cartridge 3, above the fluid level X of the ink therewithin, and the annular' chamber 19.

With this arrangement, and in order to maintain a pressure within the chamber 19 so as to positively force the ink in the cartridge 3 into writing engagement with the ball 7 on the end of the point 4, it is but periodically necessary to impart upward rotative movements to the nut 14.

My invention has been thoroughly tested and found to be completely satisfactory for the accomplishment of the above objects, and while I have shown and described a preferred embodiment, I wish it to be speciiically understood that the same is capable of modication without departure from the spirit and scope of the appended claims.

What I claim is:

l. The improvement in a gravity feeding ball point pen of the type which includes an axially elongated inkcontaining cartridge having a ball-equipped point at its normally lower end, said improvement comprising:

(a) an externally threaded tubular nut telescopically slidably received over the intermediate portion of said cartridge,

(b) an internally threaded diametrically enlarged tuybular sleeve encompassing the upper end portion of said cartridge and having screw threaded engagement at its lower end with the upper end of said nut,

(c) means sealing the upper end of said sleeve to said cartridge in downwardly spaced relation to the upper end of said cartridge and concentric with said cartridge,

(d) an annular compressible sealing ring snugly concentrically received between said cartridge and the lower end portion of said sleeve and adapted to be moved by said nut,

l(e) said sleeve and cartridge defining the cylindrical walls of an annular air-tight chamber extending between said sealing means and said sealing ring,

(f) and closure means for the upper end of said cartridge,

(g) said cartridge having port means for communication between the interior thereof and said annular chamber.

Y 4 2. The structure defined in claim 1 in whichk said seal- 'References Cited in the le of this patent ing means comprises a compressible bushing snugly slid- UNITED STATES PATENTS ably received on said cartridge, and in further combinal tion With a stop ring encompassing said carridge interme- 2488638 0 Connor No 22 19f9 diate said bushing and said port means, said cartridge 5 FOREIGN PATENTS defining a cixcumferential groove for said snap ring. 9644 570 France Feb. n 1950 

1. THE IMPROVEMENT IN A GRAVITY FEEDING BALL POINT PEN OF THE TYPE WHICH INCLUDES AN AXIALLY ELONGATED INKCONTAINING CARTRIDGE HAVING A BALL-EQUIPPED POINT AT ITS NORMALLY LOWER END, SAID IMPROVEMENT COMPRISING: (A) AN EXTERNALLY THREADED TUBULAR NUT TELESCOPICALLY SLIDABLY RECEIVED OVER THE INTERMEDIATE PORTION OF SAID CARTRIDGE, (B) AN INTERNALLY THREADED DIAMETRICALLY ENLARGED TUBULAR SLEEVE ENCOMPASSING THE UPPER END PORTION OF SAID CARTRIDGE AND HAVING SCREW THREADED ENGAGEMENT AT ITS LOWER END WITH THE UPPER END OF SAID NUT, (C) MEANS SEALING THE UPPER END OF SAID SLEEVE TO SAID CARTRIDGE IN DOWNWARDLY SPACED RELATION TO THE UPPER END OF SAID CARTRIDGE AND CONCENTRIC WITH SAID CARTRIDGE, (D) AN ANNULAR COMPRESSIBLE SEALING RING SNUGLY CONCENTRICALLY RECEIVED BETWEEN SAID CARTRIDGE AND THE LOWER END PORTION OF SAID SLEEVE AND ADAPTED TO BE MOVED BY SAID NUT, (E) SAID SLEEVE AND CARTRIDGE DEFINING THE CYLINDRICAL WALLS OF AN ANNULAR AIR-TIGHT CHAMBER EXTENDING BETWEEN SAID SEALING MEANS AND SAID SEALING RING, (F) AND CLOSURE MEANS FOR THE UPPER END OF SAID CARTRIDGE, (G) SAID CARTRIDGE HAVING PORT MEANS FOR COMMUNICATION BETWEEN THE INTERIOR THEREOF AND SAID ANNULAR CHAMBER. 